The present disclosure relates generally to impact tools for use in drilling operations, and more particularly, to fluid-actuated drilling equipment with a sonde housing having a side accessible sonde compartment.
Fluid-actuated directional percussive impact tools, such as drills, are commonly used for directional boring, which allows for the underground installation of pipes, cables, or the like without digging a trench. Drills for such operations typically include a back head for connection to a pressurized fluid source and a tool casing that houses a drill bit. A sonde housing having a sonde therein is typically arranged between the back head and the casing. The sonde can be used to register data, such as angle, rotation, or direction of the drill, temperature or the like. The data is then encoded into electro-magnetic signals and transmitted through the ground to the surface. At the surface a receiver is manually positioned over the sonde signals and the signals are decoded and steering directions relayed to the operator of the drill.
Typically a bent sub (a small, angled piece of the drill string), is used to connect the sonde housing to the tool casing. The angle of the bent sub allows the driller to steer the tool casing around obstacles that may be in the way of the planned route and/or to steer up or down to hit a set exit point of the drill.
Electronic components operating the drill, such as the sonde itself, are battery operated. Naturally, with use, the sonde battery is depleted and requires replacement. Typically, the battery is located within the sonde and the sonde is only accessible from the top of the sonde housing. Consequently, accessing the sonde battery requires disassembling the tool casing from the sonde housing to obtain the sonde. The sonde housing is typically threadedly attached to the tool casing and the prevailing method used in the industry to prevent loosening of the threaded connection during use is to weld or epoxy the joint together. Therefore, unthreading of the tool casing from the sonde housing requires heating and/or burning the threaded connection in order to untorque the tool casing from the sonde housing to access the sonde. After replacing the sonde battery and the sonde is re-inserted into the sonde housing, the threads must be re-applied with epoxy and the tool casing re-torqued onto the sonde housing and/or the tool casing is re-welded with the tool casing. This process is very inefficient and time consuming, taking anywhere from forty-five minutes to several hours to complete.
It is therefore desirable to provide a sonde housing with more direct access to the sonde in order to simplify and streamline the sonde battery replacement process.